Telephone-transmitter arm and its attachment



No. 608,504. Patented Aug. 2, I898.

w. .1. BARR. TELEPHONE TRANSMITTER ARM AND ITS ATTACHMENT.

(Application filed Oct. 30, 1897.)

(No Model.)

ATTORNEYS.

WITNESS ms upams pe'rzns co. PHOTO-LITHO. wmmmm. u c, I

UNITE STAT S PATENT Fries.

WILLIAM J. BARR, OF ASI-ITABULA, OHIO.

TELEPHONE-TRANSMITTER ARM AND ITS ATTACHMENT.,

. SPECIFICATION forming part of Letters Patent No. 608,504, dated August 2, 1898.

, Application filed October 30, 1897. Serial No. 656,899. (No model.) I

To all whom it rnayponoern:

Be it known that 1, WILLIAM J. BARR, of

Ashtabula, in the county of Ashtabula and State of Ohio, have invented a new and useful Improvement in TelephoneTransmitter Arms and Their Attachments, of which the following is a specification.

Telephone-transmitter arms have been pivoted or hinged to a base adapted to be secured to a wall or other fixed support. My invention is an improvement in such attachments. I provide the base with one or more integral trunnions and secure the transmitterarm thereto detachablyby means which insure a firm joint at all times and yet permit easy disconnection of the arm when required. I also attain an economy in manufacture and provide a more ornamental attachment than the usual one. mitter-cup integral with the arm.

My invention is shown in accompanying drawings, in which- Figure'l is a longitudinal section of my invention, the transmitter-arm being shown raised. Fig. 2 is a horizontal section of the base. Fig. 3 is afront view of the base.-

Fig. 4 is a rear view of thecap or device for securing the arm to the base-trunnions. Fig. 5 is a section showing a modification of the base-trunnions.

The hollow transmitter-arm 1 and hollow conical base 2 are formed of cast metal and in practice will be made ornamental exteriorly by nickelin g, bronzin g, or equivalent method.

The base 2has a vertical open slot 3 at its apex, which is adapted to receive the slightlyenlarged inner end of the'arm 1. The latter is hung and adapted to swing vertically on horizontal pivots or trunnions 4:, Figs. 2 and 5, which are formed integrally with the base 2 and project inward from opposite sides of the mouth 8 of the latter and at a point just back of or inward from the apex. These trunnions 4 may be cylindrical, as shown in Fig. 5, or undercut, so as to provide flanges or enlarged heads 5, as shown in Fig. 2.

The inner end of the transmitter-arm 1 is so constructed as to fit and rotate on the trunnions of either form. In other words,

the arm 1 is cut out and provided with semicircular grooves 6 in its sides, as shown in Fig. 2, which constitute bearings for the I also construct the transtrunnions 4:. The other part7 of the bearings constitutes the means for securing the arm 1 to thetrunnions and consists of a de vice in the nature of a journal-cap, which is attached to the arm 1 as follows: The said cap 7 is curved lengthwise and provided on its inner side with transverse semicircular grooves adapted to fit 011 the trunnions 4 or 5,

as the case maybe. The base end of the arm 1 is thickened, as shown in Fig. 1, the upper side having an internal shoulder 8 and the lower side being provided with a screwthreaded bore or socket 9. The cap 7 has a shoulder or claw. ll'on its upper end to engage the aforesaid shoulder 8 of the arm 1,

and its lower end is perforated transversely to receive a screw 12, which enters the socket 9. It is apparent that when the arm proper, 1, is'placed in due engagement with the trunnions 4. and the cap or fastening device 7 is arranged and secured as shown in Fig. 1 the arm 1 will be held firmly and adapted to swing vertically on the trunnions.

To compensate for wear and insure a close contact or hearing at all times, I apply a short slotted spring 13, Figs. 1 and 4, the same be- .ing clamped between the fasteningdevice 7 and socket portion 9 of said arm and its free end bearing on the trunnions, so as to tend to draw and hold the arm back' against the latter.

It is apparent the arm 1 may be quickly attached to or detached from the base 2 by simply applying or removing the screw 12 and cap 7.

The construction of the contact parts enables them'to be easily filed and smoothed, so as to fit and work with due accuracy. Furufactured economically, since it is mainly composed of four parts, and the arm, the base with trunnions,.and the cap being formed of cast metal.

As shown in Fig. 4, the cap 7 is provided with an openingl for passage of the conductor 15, which extends between the trunnions and through the arm to the carbon element 16 in the cup 17, applied to the free end of the arm. The said cup 17 is cast integral with the arm proper, 1, by which construction I attain greater solidity, strength, and durability, as well as economy in manufacture, as

. thermore, the entire attachment may be man= compared with the old method,whicl1 consists in screwing a spun-brass or hard-rubber cup onto the arm. Another advantage is attained by reason of the fact that each integral cup is bored or turned by a suitable tool to a certain depth and width, so that all are precisely alike in these dimensions, thus making the fitting and adjustment of parts accurate and uniform.

\Vhat I claim is 1. The combination, with a base having a slot or mouth, and one or more trunnions arranged within and on the side or sides of such month, the transmitter-arm whose inner end is adapted to fit and work on such trunnion or trunnions, and a fastening device which is in the nature of a cap adapted to be secured to the arm and completing the bearing, substantially as shown and described.

2. The combination, with the base having its apex provided with a vertical slot or mouth, and trunnions which are formed integrally therewith and project horizontally from opposite side of such month, of the transmitterarm whose inner end is adapted to fit loosely in such month and on the aforesaid trunnions, and the cap or fastening device adapted to lit on the opposite side of said trunnions, and secured to the arm, substantially as specified.

3. The combination, with the slotted base having one or more trunnions as specified, and the transmitter-arm having a shoulder and screw-socket, of the cap or bearing-piece adapted to [it on the trunnions, and for en gagcment with the said shoulder, and a screw for securing the free end of the cap, substantially as shown and described.

4-. The combination, with the base having a mouth and trunnions, the transmitter-arm and a bearing-cap, of a spring secured between said cap and arm, and bearing on the trnnnions, substantially as shown and described.

5. The combination with the base having a mouth provided with trunnions, and a hollow transmitter-arm litted and adapted to swing on said trunnions, of a fastening device or journal-cap having an opening, and a conductor passing through such cap, and between the trunnions, and through the arm, substantially as shown and described.

6. A base for a transmitter-arm having a slotted apex oropen 1nouth,and provided with trunnions for such arm which are arranged interiorly and oppositely in said mouth and have enlarged heads or circumferential flanges, as shown and described.

7. The combination, with the base, having an open slot or mouth provided interiorly with opposite trunnions whose heads are enlarged as specified, of the transmitter-arm having its inner end cut out or grooved transversely to fit on said trunnions, and a cap or fastening device applied on the inner side of the trunnions, as shown and described.

\VILTJAM J. I3 A RR.

\Vitnesses:

G. W. BELKNAI', EDWARD A. (inmn. 

